Flexible wax and method for producing same



cial manufacture.

2,795,596 FLEXIBLE WAX AND ISVEETHOD FOR PRODUCING AME Helmut Kolling,Dnisburg-Hamborn, and Friedrich Rappen, Oberhansen-Sterkrade, Germany,assignors to Ruhrcheniie Aktiengesellschaft, Oberhausen-Holten, Germany,a corporation of Germany No Drawing. Application May 20, 1954, SerialNo. 431,279

Claims priority, application Germany May 23, 1953 9 Claims. (Cl.260-450) catalytic carbon monoxide hydrogenation are extremely brittleso that their use for paper impregnation is very limited.

The flexibility of waxes may be determined in the following manner:

A black paper strip is coated on both sides with a film of the paraflinto be tested of 0.01 mm. in thickness.

atent This corresponds to a quantity of about 15-20 grams of paraffinper square meter of paper which is the amount most commonly applied incommercial practice. The

application of the coating to the paper is effected in the laboratory bya process similar to that used in commer- The coated paper strip is thenstretched from both sides over a rotatable mandrel of about 4 mm. indiameter and the ends are pulled several times vertically up and downpast each other. Depending upon the brittleness of the parafiin used,the wax film on the paper will rupture more or less. The measurement ofthe degree of rupture is effected photometrically by determining thebrightening developed by the rupture of the film. This value is bestdetermined by means of a photometer by means of which the percentage ofthe incident light reflected is measured. With normal slab parafiin, forexample, a whiteness of 4 is measured which means that only 4% of theincident light is reflected while 96% is absorbed. Using hard paraflinsobtained by catalytic carbon monoxide hydrogenation, a value of about 20is obtained since the film produced from the hard paraflin becomesnearly completely ruptured during the treatment described above.

When, in paper impregnation, coatings are to be obtained which areharder and more temperature-resistant than those obtainable with purenormal slab paraflin, the so-called microcrystalline waxes mustgenerally be used. Waxes of this type may be recovered from certainpetroleum fractions by relatively costly processing methods. They havepour points of 70 to 90 C. and penetration numbers of generally between3 and 20 at 20 C. The corresponding values of normal slab paraflin, asis known, range between 50 and 55 C. and 10 to 20 respectively. Whenmeasuring the flexibility in the manner described above, values ofbetween 4 and 10 are obtained depending on the type of wax tested.

Owing to their higher melting points, these microcrystalline waxes aremore temperature-resistant than normal slab paraflin. This temperatureresistance may be determined by a simple method. A paper strip is usedwhich is coated with the particular wax. In order 2,795,596 PatentedJune 11, 1957 to simulate actual service conditions, it is expedient touse the wax film which has previously been subjected to the flexibilitytest. If water of rising temperature is allowed to act from one sideupon the paper strip which has been coated on both sides with wax, itcan be observed that water drops will commence to pass through the paperat a certain temperature. This point will hereinafter be referred to astemperature-resistance. The temperature-resistance of microcrystallinewaxes ranges between about 60 and C. depending on the type of wax whilewith normal slab paraffn, water will pass through at a temperature of aslow as 50 C.

Microcrystalline waxes are used in many cases in the production of floorand boot polishes to improve the retention properties of the pastes, i.e. the ability to retain solvents without loss. They are extensivelyused at the present time as a substitute of the naturally occurringozocerite. Hard paraflin from catalytic carbon monoxide hydrogenationdoes not exhibit these retensionimproving properties to a suflicientdegree.

One object of this invention is the production from hard paraffinderived from catalytic carbon monoxide hydrogenation of a'wax havingproperties of flexibility, temtemperature resistance and retentionimproving properties at least corresponding to those of microcrystallinewaxes. This and still further objects will become apparent from thefollowing description:

It has now been found that flexible and temperatureresistant waxeshaving retention-improving properties corresponding to the differenttypes of microcrystalline waxes on the market may be produced from hardparaflin derived from catalytic carbon monoxide hydrogenation, if morethan 1 and less than 6 gram atoms of chlorine,

ice

and preferably between 2 and 4 gram atoms of chlorine,

are added to one mol of hard paraffin and the reaction product issubsequently subjected to a dehydrochlorina tron.

Hardvparafifins melting between and C. may

be produced in the conventional manner by means of the catalytic carbonmonoxide hydrogenation with the use of cobalt or iron catalysts whichare known per se. The method of producing hard waxes of this kind andthe properties thereof have frequently been described in the literature.

It isknown to chlorinate saturated hydrocarbons and to" subsequentlysplit on hydrogen chloride from the chlorination products in order toobtain hydrocarbons of the same structure having olefinic double bonds.This working method, however, involves in most cases the addition of farless than 1 gram atom of chlorine, as, for example, 0.5 gram atoms ofchlorine per mol of hydro carbon in order to obtain as high as possiblea portion of mono-olefinic products. Hard paraffin, when subjected tothis treatment, yields an olefinic product, the flexibility of which ispractically the same as that of the starting material. Also, themolecular weight of the product hasonly irn'm'ateriall'y changed. Itincreases, for example, from 650 (starting material) to 680. In socord'ance with the invention, however, when more than 1 grain atom andless than 6 gram atoms of chlorine, and preferably 2 to 4 gram atoms ofchlorine are added to each mol of hydrocarbon, there result flexiblewaxes which absolutely correspond to the microcrystalline petroleumwaxes and have none of the brittle properties of the hard paraffin. Themolecular weights of products of this type range between 800 and 1000.

It is advantageous to hydrogenate the reaction products after thedehydrochlorination. In this manner, a substantial brightening of thecolor is obtained. Moreover, the waxes lose their tackiness-withoutdetracting from their flexibility. Itis the combination of chlorinationand dehydrochlorination with a hydrogenation which constitutes thefundamental difference between the process of the invention and theknown production of olefinic hydrocarbons by chlorination anddehydrochlorination, the finished products of the process of theinvention no longer having any olefinic double bonds.

The chlorination is effected in the known manner by introducing chlorineinto the molten hard paraflin at temperatures ranging l-20 C. in excessof the melting point of the hard paraflin being processed. The Workingconditions usually employed in the chlorination of hydrocarbons areknown to anyone skilled in the art thus eliminating the necessity ofgiving particulars as to this step. The dehydrochlorination is eflectedby heating the chlorinated product for several hours at temperatures ofbetween 280 and 320 C. and preferably of 300 C. and at normalatmospheric pressure or an elevated pressure of as high as 2 kg./ squarecentimeter. It is also possible to effect the dehydrochlorination ofreduced pressures, as, for example, at an absolute pressure of 0.5kg./square centimeter. It is of advantage during the dehydrochlorinationto add small amounts of activated carbon. The hydrogenation ispreferably effected at temperatures of 200280 C. and pressures of100-200 kg./ square centimeter with the use of hydrogenation catalystswhich are known per se, as, for example, nickel or cobalt catalysts. Thehydrogenation may be effected batchwise by the slurry process orcontinuously with fixed bed catalysts. The hydrogenation period amountsto about 1-3 hours.

It is of advantage in some cases, if relatively small amounts of lowpour point portions which generally amount to -15% of the total productare separated by extraction from the reaction product after thedehydrochlorination and hydrogenation. This extraction is effected bytreating the reaction product with 2 to 5 times its quantity of solventat temperatures of 20-40 C. Suitable solvents are preferablyhydrocarbons as, for example, hexane or heptane, chlorinatedhydrocarbons, as, for example, dichloroethane, oxygenated hydrocarbons,as, for example, methanol and acetone, or mixtures of differentsolvents. It is of advantage to disperse the paraffin by spraying priorto the extraction.

A hard paraflin obtained by catalytic carbon monoxide hydrogenation, i.e. hydrocarbons boiling above approximately 400 or 450 C., isexpediently used as the starting material for the process of theinvention. Certain fractions of hard paraffin which may be recoveredtherefrom by distillation, crystallization or extraction processes arealso suitable as starting material for the process of the invention. Itis possible in this manner to prepare high melting point flexible waxeshaving specific properties.

The microcrystalline petroleum waxes include products with settingpoints of 65-70 C. which have a flexibility of 4. The flexibility ofthese waxes, however, is actually better than that of the normal slabparaflin or that of the microcrystalline waxes with pour points of about75 C. It is also better than the flexibility of the waxes prepared inthe manner described above, although the flexibility in all these casesis about 4.

For the determination of the higher flexibility, strips of about 0.5 mm.in thickness, 50 mm. in length of mm. in width are cut out from the Waxto be tested. These strips are stretched over a round stick of about 1mm. diameter so that the ends of the strip extend vertically downward. Awax strip from the above described petroleum waxes with setting pointsof 6570 C. will not break when being subjected to this severe test Whilestrips of other waxes, when subjected to this treatment, will break to amore or less large extent although they have also a flexibility of 4.

It is also possible by the process of the invention, to obtain waxeswhich meet the severe flexibility test mentioned above in spite ofhaving a much higher setting point as compared with commercialmicrocrystalline waxes, if the reaction period of thedehydrochlorination is extended to more than 10 hours and preferably to20 to 40 hours. With the dehydrochlorination effected within 3 to 5hours, the olefinic product contains residual contents of chlorine of0.1 to 0.3% which are still somewhat reduced in the subsequenthydrogenation. It is not possible by an extended dehydrochlorinationperiod to achieve a substantial decrease of the residual content ofchlorine. The extension of the dehydrochlorination period has, however,the surprising advantage that the quality of the reaction productsundergoes a substantial improvement.

This mode of operation results in waxes which meet the aforesaid severeflexibility test just as well as microcrystalline petroleum waxes havinga setting point of to C. In contrast to petroleum waxes, however, theseWaxes have setting points of to C. Thus, it is not only possible inaccordance with the invention to fully reach the extremely goodflexibility of some microcrystalline petroleum waxes but also to achievein addition a substantial increase in the setting point. In this manner,there are obtained products which are far superior to all flexible waxeshitherto on the market.

The improvement of the quality of these waxes becomes particularlyapparent if the waxes are separated into individual fractions byextraction with solvents as, for example, with heptane ordichloroethane. For this purpose, the extraction is carried out atincreasing temperatures in such a manner as to extract at first 20% byweight of the material, then again 20% by weight thereof from theremaining extraction residue and so on, until the last fraction remainswhich, in the following table, is designated with 80 to by Weight.

The extraction was applied in the same manner to a wax obtained inaccordance with the invention with the use of both, a short and a longdehydrochlorination period. As is to be noted from the flexibilityvalues given in the table, all of the individual fractions of the waxaccording to the invention exhibit low flexibility values. However, thelast extract fractions of the wax prepared with a shortdehydrochlorination period show considerably poorer flexibilities. Thepresence of fractions of poor flexibility in the waxes prepared with ashort dehydrochlorination period cannot be ascertained in determiningthe flexibility of the total wax. The poor flexibility, however, of thelast extract fractions may be the reason why the wax prepared with ashort dehydrochlorination period does not meet the severe flexibilitytest While the Wax prepared with a long dehydrochlorination periodentirely meets these conditions.

whiteness Extract fraction,

percent rapid deslow deby weight hydrohydrochlorlnachlorlnaa tion tion I020 4.0 I II 20-40 4.3 III 40-60 4.8 IV 60-80 6.1 V 80-100 8.6

The waxes prepared in accordance with the invention have propertieswhich correspond in every respect to those of the microcrystalline waxeson the market. The waxes may be used with particular advantage for paperimpregnation. They may also be used, however, as a substitute ofozocerite because they have an extremely good retention effect, that isto say, even small portions effect a very considerable reduction of thesolvent loss of pastes.

The process of the invention has the advantage that waxes which areequivalent in every respect to the so-called microcrystalline waxesobtained from petroleum may now be prepared from synthetic hydrocarbons.Moreover, the properties of these waxes may be varied within wide limitsdepending upon the reaction conditions chosen. Starting with the hardparaflins derived from catalytic carbon monoxide hydrogenation which arereadily available in large amounts, the process of the invention allowsthe production of any wax type desired in any quantity and in arelatively simple and cheap manner.

Example 1 Hard paraflin derived from catalytic. carbon monoxidehydrogenation and containing only hydrocarbons boiling above 460 C.,having a setting point of 100 C. and a penetration number at 20 C. of0.5 was chlorinated at 110-120 C. with irradiation and stirring until1.5 gram atoms of chlorine had been absorbed per mol of hydrocarbon. Thechlorinated product was mixed with 1% activated carbon and heated for 3hours at 300 C. while stirring and passing through small amounts ofnitrogen. After having filtered off the active carbon, a weaklyyellowish reaction product was obtained which had a setting point of 89C. and a penetration number of 7.5. The determination of the flexibilityeffected in the manner described in the description of the inventionresulted in a number 5. The temperature-resistance was 75 C. The hardparafiin used as the starting product showed a value of 20 whensubjected to the flexibility test.

Example 2 The finished product of Example 1 was stirred for 30 minutesat about 20 C. with the two times its quantity of ethylene chloride andsubsequently filtered. In addition to of extract there was obtained aweakly yellowish extraction residue which had a setting point of 91 C.,a penetration number of 3, a whiteness of 6 as determined by theflexibility test, and a temperature resistance of 80 C.

Example 3 Hard paraifin of the type used in Example 1 was ch1o rinateduntil 2 gram atoms of chlorine per mol of hydrocarbon had been absorbed.After the dehydrochlorination which in this experiment was effected for4 hours at about 300 C., there resulted a weakly yellowish product whichhad a setting point of 85 C., a penetration number of 17, a value of 4as determined by the flexibility test, and a temperature resistance of70 C.

Example 4 Hard parafiin of the type used in Example 1 was chlorinateduntil 2.5 gram atoms of chlorine per mol of hydrocarbon had beenabsorbed. After the dehydrochlorination which was eflected in the mannerset forth in Example 3, there resulted a yellowish product which had asetting point of 82 C., a penetration number of 34, a value of 4 asdetermined by the flexibility test, and a temperature resistance of 65C.

Example 5 Hard paraflin of the type used in Example 1 was chlorinateduntil 3 gram atoms of chlorine per mol of hydrocarbon had been absorbed.After the dehydrochlorina- Example 6 Hard paraflin of the type used inExample 1 was chlorinated until 4 gram atoms of chlorine per mol ofhydrocarbon had been absorbed. After the dehydrochlorination andsubsequent hydrogenation, effected in the manner set forth in Example 5,there was obtained a white reaction product which had a setting point of85 C., a

p n a on numbe cf 22,, a a u of 4 as d ermine by the flexibility test,and a temperature resistance of 65 C.

Example 7 A paste was prepared from 6 parts by weight of the hardparaflin used in Example 1, 24 parts by weight of :slab paraflln havinga setting point of 50-52 C., and 70 parts by weight of a mixture ofsolvent naphtha and turpentine This paste was placed in an airconditioning box for free evaporation at 20 C. The retention numbermeasured after 10 days was 30.

The retention number of a paste consisting of 4.8 parts by weight of thehard paraffin used for Example 1, 1.2 parts by weight of commercialozocerite having a setting point of 70 C., 24 parts by weight of slabparaffin and 70 parts by weight of a mixture of solvent naphtha andturpentine amounted to 20 after 10 days.

If the commercial ozocerite in the paste was replaced by the finishedproduct of Example 1, then this paste had a retention number of 12 after10 days.

Example 8 Hard paraflin derived from catalytic carbon monoxidehydrogenation, containing only hydrocarbons boiling above about 450 C.,having a setting point of 96 C. and a penetration number of 1.0 waschlorinated at l10-120 C. with irradiation and stirring until 3.5 gramatoms of chlorine had been absorbed per mol of hydrocarbon. Thechlorinated product was mixed with 1% active carbon and heated for 40hours at 300 C. while stirring and passing through small amounts ofnitrogen. After having filtered off the solid constituents, thereresulted a yellowish reaction product which contained 0.1% chlorine.

The olefinic hydrocarbon mixture was hydrogenated in a pressure vesselprovided with a stirrer with hydrogen for 3 hours at ZOO-250 C. andapressure of 120-150 kg./square centimeter using a nickel catalyst.After having filtered oil the catalyst, there resulted a weaklyyellowish product which had a setting point of 83 C.

A strip of 0.5 mm. in thickness, 50 mm. in length and 15 mm. in widthwas cut out from the wax thus prepared. This strip of wax was bent overa round stick of 1 mm. diameter so that the two ends of the stripextended vertically downward. No rupture of the wax strip could beobserved.

The process in accordance with the invention permits the production ofany type of commercial waxes having microcrystalline structures byvarying the quantity added of chlorine within the interval in accordancewith the invention of 1-6 gram atoms of chlorine per molecule ofhydrocarbon, by varying the temperature and duration of thedehydrochlorination and the conditions of the hydrogenation. The aboveexamples serve only to illustrate the process of the invention. Anyoneskilled in the art will be able to derive thereof working conditionsaccording to the invention for the production of similar flexible waxes.

We claim:

1. Process for the production of flexible waxes from hard paraflinsderived from catalytic carbon monoxide hydrogenation which compriseschlorinating, such a hard paraflin with more than 1 and less than 6 gramatoms of chlorine per mol, heating the chlorinated product at atemperature of 280 to 320 C. to efiect a dehydrochlorination of saidproduct and recovering the flexible wax formed.

2. Process according to claim 1 in which said chlorination is eflectedwith 2 to 4 gram atoms of chlorine per mol of parafiin.

3. Process according to claim 1 which includes catalyticallyhydrogenating the reaction product after said dehydrochlorination.

4. Process according to claim 1 which includes extract- -ing the lowpour point portions from the recovered flexible wax.

5. Process according to claim 1 in which the chlorinated product isheated at a temperature of 280 to 320 C. for at least ten hours for saiddehydrochlon'nation.

6. Process according to claim 5 in which said chlorinated product isheated at a temperature of 280 to 320 C. for 20 to 40 hours for saiddehydrochlorination.

7. Process according to claim 1 in which said dehydrochlorination isefiected at a temperature of about 300 C.

8. A flexible wax produced by chlorinating with more than one and lessthan six gram atoms of chlorine per mol, a hard paraflin fraction,derived from catalytic carbon monoxide hydrogenation, consisting ofhydrocarbons boiling above 400 C. and thereafter dehydrochlorinating thechlorinated product by heating to a temperature of 280 to 320 C.

9. A flexible wax produced by chlorinating with more than one and lessthan sixgram atoms of chlorine per mole, a hard parafiin fraction,derived from catalytic carbon monoxide hydrogenation, consisting ofhydrocarbons boiling above 400 C., dehydrochlorinating'the chlorinatedproduct by heating to a temperature of 280 to 320 C., and thereaftercatalytically hydrogenating the dehydrochlon'nated product.

References Cited in the file of this patent UNITED STATES PATENTS2,587,588 Berry Mar. 4, 1952 2,597,908 Stewart ct al May 27, 19522,597,910 Thaw et a1 May 27, 1952 2,651,655 Loughran -4--- Sept. 8, 1953r 2,658,090 Geiser et al Nov. 3,1953 FOREIGN PATENTS 505,898 GreatBritain May 12, 1939

1. PROCESS FOR THE PRODUCTION OF FLEXIBLE WAXES FROM HARD PARAFFINSDERIVED FROM CATALYTIC CARBON MONOXIDE HYDROGENATION WHICH COMPRISESCHLORINATING SUCH A HARD PARAFFIN WITH MORE THAN 1 AND LESS THAN 6 GRAMATOMS OF CHLORINE PER MOL, HEATING THE CHLORINATED PRODUCT AT ATEMPERATURE OF 280 TO 320* C. TO EFFECT A DEHYDROCHLORINATION OF SAIDPRODUCT AND RECOVERING THE FLEXIBLE WAX FORMED.
 8. A FLEXIBLE WAXPRODUCED BY CHLORINATING WITH MORE THAN ONE AND LESS THAN SIX GRAM ATOMSOF CHLORINE PER MOL, A HARD PARAFFIN FRACTION, DERIVED FROM CATALYTICCARBON MONOXIDE HYDROGENATION, CONSISTING OF HYDROCARBONS BOILING ABOUT400* C. AND THEREAFTER DEHYDROCHLORINATING THE CHLORINATED PRODUCT BYHEATING TO A TEMPERATURE OF 280* TO 320*C.